Study evaluates damage to rabbit eyes from exposure to 28 GHz RF-EMF
Date of review by ARPANSA
30 January 2025
Article publication date
13 January 2025
Summary
This in vivo study explored the effects of high power 28 gigahertz (GHz) radiofrequency electromagnetic fields (RF-EMF) on the ocular response and corneal damage threshold of rabbit eyes. Thirty-five male rabbits were first anaesthetised and immobilised before their right eyes were exposed to RF-EMF (28 GHz) for 6 minutes with power densities ranging from 2 to 7.5 kW/m2. The corresponding left eyes were not exposed and served as controls. The eyes were assessed prior to exposure and at 10 minutes, 1, 2 and 3 days following exposure.
No eye damage was observed at incident power densities of 3 kW/m2 and below. Some types of eye damage were observed beginning at 3.5 kW/m2 with their prevalence increasing with power density. The study estimated that the threshold for eye damage from a 6-minute exposure to 28 GHz RF-EMF is between 3.5 and 3.8 kW/m2.
Published in
Health Physics
Link to study
ARPANSA's commentary
RF-EMF at high power levels can heat biological tissue which can lead to heat-related damage. The eyes are particularly sensitive to RF heating. In their 2020 RF safety guidelines, the International Commission on Non-Ionizing Radiation Protection (ICNIRP, 2020) acknowledge a shortage of studies that use sufficiently high power to cause heat-induced injury. The lack of information on eye damage thresholds was also recently reiterated in an updated knowledge gap analysis document (ICNIRP, 2025). These types of studies are considered difficult to conduct because they must be carefully designed in order to remain within the bounds of ethical guidelines for animal research (ARVO, 2024) while still providing relevant information.
This study pioneers knowledge in this area by exploring how high-power 28 GHz RF-EMF may cause eye damage, establishing a threshold level for cornea damage. Together with other studies by the same research group on higher frequencies (Kojima et al., 2018; 2020; 2022), this body of research provides more clarity on the levels at which RF-EMF causes damage to the eyes. Such research on eye exposure is important for frequencies above 6 GHz due to the fact that RF-EMF at these frequencies is mostly absorbed on the outer surface of the skin or eyes (Sasaki et al., 2017).
In Australia, exposure to RF-EMF is governed by the Australian radiofrequency safety standard RPS-S1. Under the standard, exposure of the general public to RF-EMF at 28 GHz is restricted to 10 W/m2 for whole body exposure and 30 W/m2 for localised exposure. These levels are far below the threshold for ocular damage estimated by this study, confirming the effectiveness of RPS-S1 for protecting against the adverse effects of RF-EMF.